interface, service and DI

HelloBlazorServer/HelloBlazorServer/Components/Pages/Counter.razor

@@ -1,6 +1,12 @@
 @page "/counter"
+@using HelloBlazorServer.Interfaces
+@using HelloBlazorServer.Services
+@using HelloBlazorServer.Models
 @rendermode InteractiveServer
 
+@inject IDatabase<GangnamguPopulation> GangnamguPopulationService
+@* @inject GangnamguPopulationService GangnamguPopulationService2 // 추상화를 위해 서비스 직접 주입 자제*@
+
 <PageTitle>Counter</PageTitle>
 
 <h1>Counter</h1>
@@ -12,6 +18,12 @@
 @code {
     private int currentCount = 0;
 
+    protected override void OnInitialized()
+    {
+        var data1 = GangnamguPopulationService.Get();
+        // var data1 = GangnamguPopulationService2.Get();
+    }
+
     private void IncrementCount()
     {
         currentCount++;

HelloBlazorServer/HelloBlazorServer/Interfaces/IDatabase.cs

@@ -0,0 +1,22 @@
+using HelloBlazorServer.Models;
+
+namespace HelloBlazorServer.Interfaces
+{
+    public interface IDatabase<T>
+    {
+        // Select All
+        List<T>? Get();
+
+        // Select using ID
+        T GetDetail(int? id);
+
+        // Create
+        void Create(T entity);
+
+        // Update
+        void Update(int? id, T entity);
+
+        // Delete
+        void Delete(int? id);
+    }
+}

HelloBlazorServer/HelloBlazorServer/Program.cs

@@ -1,9 +1,13 @@
 using HelloBlazorServer.Components;
 using HelloBlazorServer.Components.Account;
 using HelloBlazorServer.Data;
+using HelloBlazorServer.Interfaces;
+using HelloBlazorServer.Models;
+using HelloBlazorServer.Services;
 using Microsoft.AspNetCore.Components.Authorization;
 using Microsoft.AspNetCore.Identity;
 using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Storage;
 
 namespace HelloBlazorServer
 {
@@ -41,6 +45,9 @@ namespace HelloBlazorServer
 
             builder.Services.AddSingleton<IEmailSender<ApplicationUser>, IdentityNoOpEmailSender>();
 
+            builder.Services.AddDbContext<BlazorServerDbContext>();
+            builder.Services.AddScoped<IDatabase<GangnamguPopulation>, GangnamguPopulationService>();
+
             var app = builder.Build();
 
             // Configure the HTTP request pipeline.

HelloBlazorServer/HelloBlazorServer/Services/GangnamguPopulationService.cs

@@ -0,0 +1,70 @@
+using HelloBlazorServer.Interfaces;
+using HelloBlazorServer.Models;
+
+namespace HelloBlazorServer.Services
+{
+    public class GangnamguPopulationService : IDatabase<GangnamguPopulation>
+    {
+        private readonly BlazorServerDbContext _context;
+
+        public GangnamguPopulationService(BlazorServerDbContext context)
+        {
+            _context = context;
+        }
+
+        public void Create(GangnamguPopulation entity)
+        {
+            if (_context.GangnamguPopulations == null)
+                throw new NullReferenceException();
+
+            _context.GangnamguPopulations.Add(entity);
+            _context.SaveChanges();
+        }
+
+        public void Delete(int? id)
+        {
+            if (_context.GangnamguPopulations == null)
+                throw new NullReferenceException();
+
+            var validData = _context.GangnamguPopulations.Find(id);
+            if (validData == null)
+                return;
+
+            _context.GangnamguPopulations.Remove(validData);
+            _context.SaveChanges();
+        }
+
+        public List<GangnamguPopulation>? Get()
+        {
+            if (_context.GangnamguPopulations == null)
+                throw new NullReferenceException();
+
+            return _context.GangnamguPopulations.ToList();
+        }
+
+        public GangnamguPopulation GetDetail(int? id)
+        {
+            if (_context.GangnamguPopulations == null)
+                throw new NullReferenceException();
+
+            var validData = _context.GangnamguPopulations.Find(id);
+            if (validData == null)
+                return null;
+
+            return validData;
+        }
+
+        public void Update(int? id, GangnamguPopulation entity)
+        {
+            if (_context.GangnamguPopulations == null)
+                throw new NullReferenceException();
+
+            var validData = _context.GangnamguPopulations.Find(id);
+            if (validData == null)
+                return;
+
+            _context.GangnamguPopulations.Update(entity);
+            _context.SaveChanges();
+        }
+    }
+}